Hi all, I'm moving to the UK in August for school and being the iPhone addict I am I deemed it necessary to have an iPhone while I'm across the pond. I recently found out that I'll need an unlocked iPhone in order to use it on England's mobile networks. I'm not too familiar with this territory so I was wondering if you all could help me out. If I simply go buy an unlocked iPhone from the Apple store, take it to England, set up a plan with Vodafone and pop a Vodafone sim card into my phone, will it work? When I return to the states can I just swap my Vodafone sim with my AT&T sim (assuming my number in the states is kept active) and continue using my phone in the states? Is it that straightforward? I've also heard from some sources that unlocked iPhones can't function on 3g networks? I find that hard to believe. I guess my other option is to keep my locked AT&T iphone 4 in the states and buy a new on-contract phone through Vodafone or O2 and go about my business that way. Any help is appreciated! Thanks!